Champion Units (1500 armor scraps):- Increases NPC efficiency by the most it can be increased- Gives players a 30% damage and size increase buff periodically for 2 minutes

These are rarely utilised these days but they are very powerful: reaching champion can turn the tide of battle due to the 30% damage buff. In Cataclysm, it appears that upgrading units will provide around a 100% increase in efficiency. For example, a caster mine guardian has 10,000 hitpoints and Fireball's for 5k. When upgraded, the caster mine guardian will have 22,000 hitpoints and Fireball for an average of 13,000.